/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the  "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
/*
 * $Id: ApplyXPath.java 470245 2006-11-02 06:34:33Z minchau $
 */
// This file uses 4 space indents, no tabs.
package ApplyXPath;

import java.io.FileInputStream;
import java.io.OutputStreamWriter;

import javax.xml.parsers.DocumentBuilderFactory;
import javax.xml.transform.OutputKeys;
import javax.xml.transform.Transformer;
import javax.xml.transform.TransformerFactory;
import javax.xml.transform.dom.DOMSource;
import javax.xml.transform.stream.StreamResult;

import org.apache.xpath.XPathAPI;
import org.w3c.dom.Document;
import org.w3c.dom.Node;
import org.w3c.dom.traversal.NodeIterator;
import org.xml.sax.InputSource;

/**
 * 
 * @author wangqi.aguai.2011@gmail.com
 * 
 *         Test class for Xalan XPath 2.0 functions
 * 
 */
public class ApplyXPath {
	protected String filename = null;
	protected String xpath = null;

	/** Process input args and execute the XPath. */
	public void doMain(String[] args) throws Exception {
		filename = args[0];
		xpath = args[1];

		if ((filename != null) && (filename.length() > 0) && (xpath != null)
				&& (xpath.length() > 0)) {
			// Tell that we're loading classes and parsing, so the time it
			// takes to do this doesn't get confused with the time to do
			// the actual query and serialization.
			System.out.println("Loading classes, parsing " + filename
					+ ", and setting up serializer");

			// Set up a DOM tree to query.
			InputSource in = new InputSource(new FileInputStream(filename));
			DocumentBuilderFactory dfactory = DocumentBuilderFactory
					.newInstance();
			dfactory.setNamespaceAware(true);
			Document doc = dfactory.newDocumentBuilder().parse(in);

			// Set up an identity transformer to use as serializer.
			Transformer serializer = TransformerFactory.newInstance()
					.newTransformer();
			serializer
					.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes");

			// Use the simple XPath API to select a nodeIterator.
			System.out.println("Querying DOM using " + xpath);
			NodeIterator nl = XPathAPI.selectNodeIterator(doc, xpath);

			// Serialize the found nodes to System.out.
			System.out.println("<output>");

			Node n;
			while ((n = nl.nextNode()) != null) {
				if (isTextNode(n)) {
					// DOM may have more than one node corresponding to a
					// single XPath text node. Coalesce all contiguous text
					// nodes
					// at this level
					StringBuffer sb = new StringBuffer(n.getNodeValue());
					for (Node nn = n.getNextSibling(); isTextNode(nn); nn = nn
							.getNextSibling()) {
						sb.append(nn.getNodeValue());
					}
					System.out.print(sb);
				} else {
					serializer.transform(new DOMSource(n), new StreamResult(
							new OutputStreamWriter(System.out)));
				}
				System.out.println();
			}
			System.out.println("</output>");
		} else {
			System.out.println("Bad input args: " + filename + ", " + xpath);
		}
	}

	/** Decide if the node is text, and so must be handled specially */
	static boolean isTextNode(Node n) {
		if (n == null)
			return false;
		short nodeType = n.getNodeType();
		return nodeType == Node.CDATA_SECTION_NODE
				|| nodeType == Node.TEXT_NODE;
	}

	/** Main method to run from the command line. */
	public static void main(String[] args) throws Exception {
		ApplyXPath app = new ApplyXPath();
		app.doMain(new String[] { "foo.xml", "/doc/name[ends-with(@first,'d')]" });
	}

}
